Friday’s episode of Hawaii Five-0 marks the directorial debut of Alex O’Loughlin, but he encountered some pushback from a surprisingly difficult actor on set — himself.

Though the hour focuses heavily on Danny (Scott Caan) and Adam (Ian Anthony Dale) in two distinct storylines — Danny faces the ex-wife of the man who shot him, while Adam is framed for murder — McGarrett still plays a large role in the episode as he’s forced to clear Adam’s name and protect his task force.

“I was the most difficult part of directing,” O’Loughlin tells EW with a laugh, explaining that his extra duties as director prevented him from doing enough prep work as an actor.

Typically, the actor explains, he studies every beat of every scene, putting in hours of homework before stepping foot on set. But this time around, his focus was heavily on directing. “I was [acting] in the script a lot more than I would’ve liked to have been,” he says. “I really didn’t do as much acting homework as I usually do. I just didn’t have time. I think next time hopefully I’ll be in it less, or I’ll have time to do my acting prep as well as my directing work. That was definitely the most frustrating for me.”

But O’Loughlin says everything else about directing felt “strangely natural” to him. “I really loved it,” he says. “I didn’t know how it was going to be with actors, I just thought I would try to be the way I enjoy directors to be with me, which is informed, and informative, and open, and full of questions, and collaborative, and have a passionate connection to a story. For the most part the actors really felt that, and I had a lot of positive feedback from the actors. So that was great.”

Karen Neal/CBS

The crux of O’Loughlin’s episode lies in Danno’s story, in which he’s reunited with the ex-wife of his shooter, whom he had rescued from a domestic abuse situation years prior in New Jersey. “The heartbeat of my script is a violence-against-women story, which is something that I feel passionately about,” he says. “It was great to be able to tell these stories and represent hope for the unrepresented women all across the world who are fighting a horrible fight that they should never have to fight. That meant a lot to me.”

Check out a sneak peek from the hour above. Hawaii Five-0 airs Fridays at 9 p.m. ET on CBS. Read our interview with O’Loughlin on his future with the show here.